Cohesive Zone Law Extraction from an Experimental Peel Test

Abstract

The measurement of interface mechanical properties between an adhesive layer and a substrate is significant for optimization of a high-quality interface. A common method for measuring these properties is the peel test. Although analytical models exist for the peeling of elastic adhesives from smooth surfaces, there is a need for rigorous experiments in this area. Tests are conducted using a peel arrangement capable of peel angles from 0° to 180°. Experimental validation is achieved through a series of displacement-controlled tests using elastic adhesive tapes. The steady-state peel force is measured at each angle and compared to the predicted values based upon the governing relations of Kendall and Rivlin.

The fibrillation zone of a simple adhesive material is imaged at the contact point between the adhesive and a rigid surface. By quantifying the size of this process zone, an inverse formulation is developed to extract an angle-dependent cohesive zone law based upon finite deformation beam theory. The adhesion energy during a peel test is then determined along with the force distribution in the process zone. This local method of determining the adhesion energy is compared to the global method of Rivlin in the context of finite deformations, showing good agreement.